Question

2

A circle is described by the equation x² + y2 + 14x + 2y + 14 =
0. What are the coordinates for the center of the circle and
the length of the radius?
(-7, -1), 36 units
(7,1), 36 units
• (7, 1), 6 units
(-7, -1), 6 units
Dona

Answer 1

(-7, -1), 6 units

Explanation:

x² + y² + 14x + 2y + 14 = 0

x² + 14x + y² + 2y = -14

Complete the squares.

x² + 14x + 49 + y² + 2y + 1 = -14 + 49 + 1

(x + 7)² + (y + 1)² = 36

(x + 7)² + (y + 1)² = 6²

The center is at (-7, -1) and the radius is 6.